What is Tower AC? A tower AC or floor standing air conditioner is a portable device comprising two units- an indoor unit and an outdoor unit. The indoor unit can be placed in any corner of the room, while the outdoor unit is installed outside the house to throw out warm aiThe tower ACs are portable and comprise two units- internal and external. While the indoor unit can be placed at any corner of the room, the outdoor unit is installed outside the house to throw out the warm air. What is a standing AC called? A standing AC is called a floor standing air conditioner or a tower AC.